This invention relates to a coin-operated, car-wash wet-vacuum cleaning machine, and more particularly to means in the machine for preventing a hot-water hose and spray valve from freezing between operations during cold weather.
Coin-operated vacuum cleaners are often installed at self-service car washes for the purpose of cleaning carpets and upholstery in automobiles, motor homes, vans, recreational vehicles, or any type of vehicle with carpet or upholstery, including boats or trailers. With the development of wet and dry vacuum cleaners for floor carpets, there has been a demand for similar carpet cleaning machines in coin-operated car wash bays. The technique is to supply hot water under pressure to a manually operated valve for spraying. Soap is mixed with the hot water sprayed to effect better cleaning. The dirty water is then vacuumed into a cannister and later discharged.
A problem arises in utilizing this wet-vacuum cleaning technique in open car-wash bays during cold weather since enough time may lapse between customers to allow the water in the line to the spray valve to freeze. This problem is exacerbated by the small diameter of the hot water line to the spray valve, and length of that line provided to allow areas in the far reaches of the vehicle to be cleaned. Yet there is a demand for self-service wet-vacuum cleaners in car washes during cold weather.